The Dutch Tunnel

The third floor of the eastern side of the castle, directly above the British quarters, was occupied by the Dutch.

On the outside wall of the castle at this point, extending from the third floor downwards, was a buttress, with a balustraded balcony at the top.

The prisoners had often wondered whether this buttress was hollow or not, and in the spring of 1942, Captain Machiel Van den Heuval decided to find out.

On the inside face of the eastern external wall of the castle, 2 floors above ground level, was a urinal. At waist level, a hole measuring about 18 inches square was cut in the urinal, and a horizontal passage dug inside the wall, running parallel to the east face of the castle in the direction of the buttress. After about 6 feet of tunnelling, the Dutch arrived at a hollow cavity directly adjacent to the balcony at the top of the buttress. This was understood to be a blocked off hallway that once provided access to the balcony. From here, the tunnellers started a second shaft, running diagonally downwards into the buttress. The buttress was indeed found to be hollow, and a horizontal tunnel was immediately started at the bottom of the buttress, several feet below ground level. Only nine yards of tunnelling would have been required to reach the steep downward slope leading away from the castle.

The German security officer, however, probably after picking up tunnelling noises from the sound detectors which were installed throughout the castle, decided to investigate the buttress. A hole was knocked in one of the walls of the buttress at ground level. Upon hearing the noises from this hammering, the two tunnellers immediately stopped work and scrambled up the inside of the buttress using a ladder. The ladder was quickly hoisted up shortly after, but not quickly enough. A German guard began climbing upwards in pursuit of the tunnellers. The tunnellers threw everything they could by way of debris at him down their chute entrance, but to no effect.
The Germans found much escape paraphernalia inside the tunnel, including uniforms, and perhaps most importantly, one of the Dutch dummies which had so successfully covered up absences at roll calls for some time.